Conventionally, in a case of continuously providing a web material (continuous long recording medium) to an apparatus such as a printer, for example, there has been employed a structure for preparing a rolled body obtained by winding the web material and sequentially feeding the web material from the rolled body. In particular, in a case of a large printer, a large heavy web material is used in many cases. For this reason, the web material is wound around a paper tube, which is a core, to thereby form the rolled body. The paper tube is a cylinder made of a cardboard, synthetic resin, or the like, and is capable of holding the heavy web material without being largely deformed. Note that, the term “paper tube” is generally used, but it is not limited to a tubular member made of paper, and a tubular member or the like made of synthetic resin such as vinyl chloride is also widely used.
When a long support shaft penetrating the paper tube is provided so as to set the rolled body having the structure, in which the web material is wound around the paper tube, in the apparatus as described above, the apparatus is increased in size and an operation of mounting and dismounting the rolled body becomes complicated. Accordingly, there is used an apparatus for holding both end portions of the rolled body, particularly, both end portions of the paper tube.
As a device for holding the end portions of the rolled body, a mechanism for supporting the paper tube from an inside is generally used. However, in a case where there is a gap between an inner surface of the paper tube and the supporting mechanism, wobbling is caused when the web material is fed or wound. As a result, advancement and retraction of the web material cannot be smoothly performed, and there is a possibility that an edge portion of the web material is folded or a skew is caused. In general, an inner diameter of the paper tube is uniformly set to a specified dimension, for example, 3 inches (76.2 mm), but there is a possibility that an error of about several mm is produced. In such a case, a gap is formed between the inner surface of the paper tube and the supporting mechanism as described above, whereby the web material cannot be smoothly fed or wound.
In view of the above, Patent Document 1 (JP 05-77976 A), for example, proposes a device for holding the end portions of the rolled body without causing wobbling, by using a plurality of abutment members to be brought into press contact with the inner surface of the paper tube from the inside.
In the holder described in Patent Document 1 (JP 05-77976 A), the plurality of abutment members movable in the radial direction support the paper tube while being brought into press contact with the inner surface of the paper tube from the inside, thereby making it possible to eliminate the wobbling. However, in the holder, in the case of holding the paper tube, locking pawls are first disengaged from a gear, the holder is inserted into the paper tube, and the abutment members themselves are moved to be abutted against the inner surface of the paper tube. Then, the locking pawls are engaged with the gear again, thereby fixing the abutment members. A series of processes are manually performed, so the processes are quite troublesome. Further, Patent Document 1 does not disclose a mechanism for performing the process of manually moving the abutment members themselves to be abutted against the inner surface of the paper tube and the process of engaging the locking pawls with the gear again, in a state where the holder is inserted into the paper tube. If the mechanism can be realized, an extremely complicated structure may be required.